(19)
(11) EP 0 789 247 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.04.1998 Bulletin 1998/16

(43) Date of publication A2:
13.08.1997 Bulletin 1997/33

(21) Application number: 97102206.6

(22) Date of filing: 12.02.1997
(51) International Patent Classification (IPC)6: G01R 29/02
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 12.02.1996 US 589035

(71) Applicant: Snap-on Technologies, Inc.
Chrystal Lake, Illinois 60014 (US)

(72) Inventors:
  • Villa, Charles N.
    San Jose, California 95125 (US)
  • Andersson, Claes Georg
    Fremont, California 94536 (US)

(74) Representative: Steil, Christian, Dipl.-Ing. et al
Witte, Weller, Gahlert, Otten & Steil, Patentanwälte, Rotebühlstrasse 121
70178 Stuttgart
70178 Stuttgart (DE)

   


(54) Method and apparatus for detection and acquisition of automotive fuel injector voltage signal pulse width


(57) A method and apparatus for detecting and displaying automotive fuel injector voltage signal pulse width which includes signal detection circuits (104, 123, 125) for capturing the rising and falling edges of an input signal (100) having positive and negative voltage swings is disclosed. Upon detecting a rising edge or a falling edge of a positive or negative voltage of the input signal (100), a corresponding software routine is executed to carry out the process of measuring the pulse width of a pulse (10; 16; 24; 34; 46; 52; 60; 70) of the input signal (100). The measured pulse width is then displayed in numerical and/or histogramic formats.






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